KR20040036915A - Naphthyridine Derivative - Google Patents

Abstract

The present invention provides a novel naphthyridine derivative having analgesic action, low toxicity, and exerting a therapeutic effect of diabetic neuropathy, wherein the derivative is represented by the formula (1).

<Formula 1>

[Wherein, R ¹ , R ² , R ³ and R ⁴ represent groups described in the specification.]

Description

Naphthyridine Derivative

The present inventors discovered a novel naphthyridine derivative having an analgesic effect and completed the invention related to the derivative [PCT / JP98 / 03045 (International Publication No. WO99 / 02527). By the way, in the following studies, the present inventors have little effect of improving the symptoms in the case of a disease in which the derivative is damaged, for example diabetic neuropathy, and it is difficult to exhibit the desired analgesic effect. It was confirmed that administration of the derivative thereof may cause side effects such as hyperthyroidism, for example.

The present invention relates to novel naphthyridine derivatives.

It is therefore an object of the present invention to provide novel naphthyridine derivatives which have superior pharmacological properties than the derivatives developed by the present inventors and are more useful in the pharmaceutical field.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to achieve the said objective, the present inventors discovered that the novel derivative represented by following formula (1) matches the said objective, and came to complete this invention here.

The present invention provides a novel naphthyridine derivative represented by the following formula (1).

Wherein R ¹ represents a hydrogen atom or a lower alkyl group; R ² represents a hydrogen atom, a lower alkyl group, a cycloalkyl group, a phenyl group or a phenyl lower alkyl group which may have 1-3 lower alkoxy groups on the phenyl ring; R ³ and R ⁴ are each a group -YOZR ⁵ (wherein Y is a lower alkylene group, Z is a single bond or a lower alkylene group, and R ⁵ is a halogen atom as a substituent, a lower alkoxy group, a lower alkyl group, a halogen substituted lower alkyl group). , Phenyl group having 1-3 groups selected from the group containing methylenedioxy group, hydroxy group, 2,2-di (lower alkoxycarbonyl) ethyl group and 2,2-di (lower alkoxycarbonyl) vinyl group) Or one of R ³ and R ⁴ is a group -YOZR ⁵ (wherein Y, Z and R ⁵ are the same as above) and the other represents a lower alkyl group, a phenyl group or a phenyl lower alkyl group. Provided that R ² is a phenyl lower alkyl group which may have 1-3 lower alkoxy groups on the phenyl ring, and at least one of R ³ and R ⁴ has benzyloxy lower alkyl group which has 1-3 lower alkoxy groups on the benzene ring Is excluded.]

The present invention also provides a pharmaceutical composition containing the naphthyridine derivative and a pharmaceutically acceptable carrier, in particular, the pharmaceutical composition which is an analgesic agent, the pharmaceutical composition which is a diabetic neuropathy agent, and the pharmaceutical composition which is an adenosine enhancer.

The present invention also provides an analgesic method for a patient, a method for treating diabetic neuropathy, and a method for enhancing adenosine in a patient, comprising administering an effective amount of the naphthyridine derivative to a patient in need thereof.

Hereinafter, the derivative of the present invention will be described in detail.

The following each group used by the said General formula (1) which shows derivative of this invention, and each other formula in this specification is as follows, respectively. In this specification, the word "lower" which can be used about each group containing carbon shall be used by the meaning of "with 1-6 carbon atoms."

As a lower alkyl group, C1-C6 linear or branched alkyl groups, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert- butyl, pentyl, hexyl group, are mentioned, for example.

As a cycloalkyl group, C3-C8 cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, a cyclooctyl group, are mentioned, for example.

As a lower alkoxy group, C1-C6 linear or branched alkoxy groups, such as a methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy group, are mentioned, for example.

As a lower alkylene group, C1-C6 linear or branched alkylene groups, such as methylene, ethylene, ethylidene, trimethylene, tetramethylene, pentamethylene, hexamethylene group, are mentioned, for example.

As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom can be illustrated.

As the halogen-substituted lower alkyl group, for example, a perhalogeno- (C _1-6 -alkyl) group having a halogen atom selected from the group consisting of fluorine, chlorine, bromine and iodine atoms as substituents, in particular perfluoro- ( C _1-6 -alkyl) group, specifically, trifluoromethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, undecafluoropentyl, tridecafluorohexyl group, etc. are mentioned. .

Examples of the 2,2-di (lower alkoxycarbonyl) ethyl group include 2,2-dimethoxycarbonylethyl, 2,2-diethoxycarbonylethyl, 2,2-dipropoxycarbonylethyl, 2 2,2-di (C _1-6 -alkoxy-carbonyl) ethyl groups such as 2,2-dibutoxycarbonylethyl, 2,2-dipentyloxycarbonylethyl and 2,2-dihexyloxycarbonylethyl groups Can be mentioned.

Examples of the 2,2-di (lower alkoxycarbonyl) vinyl group include 2,2-dimethoxycarbonylvinyl, 2,2-diethoxycarbonylvinyl, 2,2-dipropoxycarbonylvinyl, 2,2-di (C _1-6 -alkoxy-carbonyl) such as 2,2-dibutoxycarbonylvinyl, 2,2-dipentyloxycarbonylvinyl and 2,2-dihexyloxycarbonylvinyl group Vinyl group is mentioned.

Examples of the phenyl lower alkyl group include phenyl-C _1-6- such as benzyl, 1-phenylethyl, 2-phenylethyl, 3-phenylpropyl, 4-phenylbutyl, 5-phenylpentyl, and 6-phenylhexyl group. Alkyl group is mentioned.

As a phenyl lower alkyl group which may have 1-3 lower alkoxy groups on a phenyl ring, in addition to the phenyl lower alkyl group of the said illustration, For example, 2-methoxybenzyl, 3-methoxybenzyl, 4-methoxybenzyl , 4-ethoxybenzyl, 4-propoxybenzyl, 4-butoxybenzyl, 4-pentyloxybenzyl, 4-hexyloxybenzyl, 2,3-dimethoxybenzyl, 2,4-dimethoxybenzyl, 2,5 -Dimethoxybenzyl, 2,6-dimethoxybenzyl, 3,4-dimethoxybenzyl, 3,5-dimethoxybenzyl, 2,3,4-trimethoxybenzyl, 2,3,5-trimethoxybenzyl , 2,4,5-trimethoxybenzyl, 3,4,5-trimethoxybenzyl, 3,4,5-triethoxybenzyl, 1- (4-methoxyphenyl) ethyl, 2- (4- Methoxyphenyl) ethyl, 3- (4-methoxyphenyl) propyl, 4- (4-methoxyphenyl) butyl, 5- (4-methoxyphenyl) pentyl, 6- (4-methoxyphenyl) hexyl, 1- (3,4,5-trimethoxyphenyl) ethyl, 2- (3,4,5-trimethoxyphenyl) ethyl, 3- (3,4,5-trimethoxyphenyl) propyl, 4- (3,4,5-trimethoxyphenyl) butyl, 5- (3,4,5-trimethoxyphenyl) pentyl, 6- ( 3,4,5-trimethoxyphenyl) may be mentioned the phenyl ring, C _1-6- alkoxy phenyl -C _1-6- alkyl group that may have 1-3 above, such as a hexyl group.

Substituents include halogen atom, lower alkoxy group, lower alkyl group, halogen substituted lower alkyl group, methylenedioxy group, hydroxy group, 2,2-di (lower alkoxycarbonyl) ethyl group and 2,2-di (lower alkoxycarbonyl) vinyl group As a phenyl group which may have 1-3 groups selected from the group to mention, each group illustrated below is mentioned in addition to an unsubstituted phenyl group.

2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 4-fluorophenyl, 4-bromophenyl, 4-iodinephenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 4-ethoxyphenyl, 4-propoxyphenyl, 4-butoxyphenyl, 4-pentyloxyphenyl, 4-hexyloxyphenyl, 2-trifluoromethylphenyl, 3-trifluoromethylphenyl, 4-trifluoromethylphenyl , 4-pentafluoroethylphenyl, 4-heptafluoropropylphenyl, 4-nonafluorobutylphenyl, 4-undecafluoropentylphenyl, 4-tridecafluorohexylphenyl, 2,3-methylenedioxy Phenyl, 3,4-methylenedioxyphenyl, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 2- (2,2-dimethoxycarbonylethyl) phenyl, 3- (2,2 -Dimethoxycarbonylethyl) phenyl, 4- (2,2-dimethoxycarbonylethyl) phenyl, 4- (2,2-diethoxycarbonylethyl) phenyl, 4- (2,2-dipropoxycar Carbonylethyl) phenyl, 4- (2,2-dibutoxycarbonylethyl) phenyl, 4- (2,2-dipentyloxycarbo Ethyl) phenyl, 4- (2,2-dihexyloxycarbonylethyl) phenyl, 2- (2,2-dimethoxycarbonylvinyl) phenyl, 3- (2,2-dimethoxycarbonylvinyl) phenyl, 4- (2,2-dimethoxycarbonylvinyl) phenyl, 4- (2,2-diethoxycarbonylvinyl) phenyl, 4- (2,2-dipropoxycarbonylvinyl) phenyl, 4- (2 , 2-dibutoxycarbonylvinyl) phenyl, 4- (2,2-dipentyloxycarbonylvinyl) phenyl, 4- (2,2-dihexyloxycarbonylvinyl) phenyl, 2,3-dichlorophenyl, 2,4-dichlorophenyl, 2,5-dichlorophenyl, 2,6-dichlorophenyl, 3,4-dichlorophenyl, 3,5-dichlorophenyl, 2,4,6-trichlorophenyl, 2,3-dime Methoxyphenyl, 2,4-dimethoxyphenyl, 2,5-dimethoxyphenyl, 2,6-dimethoxyphenyl, 3,4-dimethoxyphenyl, 3,5-dimethoxyphenyl, 2,4,6-tri Methoxyphenyl, 2,3,4-trimethoxyphenyl, 2,3,5-trimethoxyphenyl, 2,4,5-trimethoxyphenyl, 3,4,5-trimethoxyphenyl, 2, 3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dime Phenyl, 3,5-dimethylphenyl, 2,4,6-trimethylphenyl, 2,3,4-trimethylphenyl, 2,3,5-trimethylphenyl, 2,4,5-trimethylphenyl, 3,4,5 -Trimethylphenyl, 2,3-bis (trifluoromethyl) phenyl, 2,4-bis (trifluoromethyl) phenyl, 2,5-bis (trifluoromethyl) phenyl, 2,6-bis (tri Fluoromethyl) phenyl, 3,4-bis (trifluoromethyl) phenyl, 3,5-bis (trifluoromethyl) phenyl, 2,4,6-tris (trifluoromethyl) phenyl, 2,3 , 4-tris (trifluoromethyl) phenyl, 2,3,5-tris (trifluoromethyl) phenyl, 2,4,5-tris (trifluoromethyl) phenyl, 3,4,5-tris ( Trifluoromethyl) phenyl, 2,3-dihydroxyphenyl, 2,4-dihydroxyphenyl, 2,5-dihydroxyphenyl, 2,6-dihydroxyphenyl, 3,4-dihydroxy Phenyl, 3,5-dihydroxyphenyl, 2,4,6-trihydroxyphenyl, 2,3,4-trihydroxyphenyl, 2,3,5-trihydroxyphenyl, 2,4,5- Trihydroxyphenyl, 3,4,5-trihydroxyphenyl, 2,4-bis (2,2-dipentyloxycarbonylethyl) phenyl, 3,5-bis (2,2-dipentyloxycarbonylethyl) phenyl, 2,5-bis (2,2-dipentyloxycarbonylethyl) Phenyl, 2,6-bis (2,2-dipentyloxycarbonylethyl) phenyl, 2,4,6-tris (2,2-dipentyloxycarbonylethyl) phenyl, 2,4-bis (2, 2-dipentyloxycarbonylvinyl) phenyl, 3,5-bis (2,2-dipentyloxycarbonylvinyl) phenyl, 2,5-bis (2,2-dipentyloxycarbonylvinyl) phenyl, 2 , 6-bis (2,2-dipentyloxycarbonylvinyl) phenyl, 2,4,6-tris (2,2-dipentyloxycarbonylvinyl) phenyl, 3,4-methylenedioxy-5-meth Methoxyphenyl, 2,3-methylenedioxy-4-methoxyphenyl, 2,3-methylenedioxy-5-methoxyphenyl, 5-hydroxy-3,4-methylenedioxyphenyl, 5-hydroxy- 2,3-methylenedioxyphenyl, 4-hydroxy-2,3-methylenedioxyphenyl, 3-hydroxy-4,5-dimethoxyphenyl, 4-hydroxy-3,5-dimethoxyphenyl, 4 -Hydroxy-2,6-dimethoxyphenyl, 3,5-dihydroxy-4-methoxyphenyl, 2,6-dihydrate Hydroxy-4-methoxyphenyl, 4-hydroxy-3,5-dimethylphenyl, 4-methoxy-3,5-dimethylphenyl, 4-hydroxy-3,5-di-t-butylphenyl, 4- Methoxy-3,5-di-t-butylphenyl, 2-chloro-4-methoxyphenyl, 4-chloro-2-methoxyphenyl, 2-chloro-4-methylphenyl, 4-chloro-2-methylphenyl, 2-chloro-4-trifluoromethylphenyl, 4-chloro-2-trifluoromethylphenyl, 2-chloro-4,5-methylenedioxyphenyl, 5-chloro-2,3-methylenedioxyphenyl, 2- Chloro-4-hydroxyphenyl, 4-chloro-2-hydroxyphenyl, 2-chloro-4- (2,2-dimethoxycarbonylethyl) phenyl, 4-chloro-2- (2,2-dimethoxy Carbonylethyl) phenyl, 2-chloro-4- (2,2-dimethoxycarbonylvinyl) phenyl, 4-chloro-2- (2,2-dimethoxycarbonylvinyl) phenyl, 3-methoxy-4 -Methylphenyl, 4-methoxy-3-methylphenyl, 3-methoxy-4-trifluoromethylphenyl, 4-methoxy-3-trifluoromethylphenyl, 3-hydroxy-4-methoxyphenyl, 4-hydrate Roxy-3-methoxyphenyl, 4- (2,2-dimethoxy Levonylethyl) -2-methoxyphenyl, 2- (2,2-dimethoxycarbonylethyl) -4-methoxyphenyl, 4- (2,2-dimethoxycarbonylvinyl) -2-methoxyphenyl , 2- (2,2-dimethoxycarbonylvinyl) -4-methoxyphenyl, 3-methyl-4-trifluoromethylphenyl, 4-methyl-3-trifluoromethylphenyl, 4-methyl-2,3 Methylenedioxyphenyl, 2-methyl-3,4-methylenedioxyphenyl, 3-hydroxy-4-methylphenyl, 4-hydroxy-3-methylphenyl, 4- (2,2-dimethoxycarbonylethyl) 2-methylphenyl, 2- (2,2-dimethoxycarbonylethyl) -4-methylphenyl, 4- (2,2-dimethoxycarbonylvinyl) -2-methylphenyl, 2- (2,2-dimethoxy Carbonylvinyl) -4-methylphenyl, 2,3-methylenedioxy-4-trifluoromethylphenyl, 3,4-methylenedioxy-5-trifluoromethylphenyl, 3-hydroxy-4-trifluoromethylphenyl , 4-hydroxy-3-trifluoromethylphenyl, 4- (2,2-dimethoxycarbonylethyl) -2-trifluoromethylphenyl, 2- (2,2-dimethoxycarbonylethyl) -4- Trifluor Methylphenyl, 4- (2,2-dimethoxycarbonylvinyl) -2-trifluoromethylphenyl, 2- (2,2-dimethoxycarbonylvinyl) -4-trifluoromethylphenyl, 2,3-methylenedi Oxy-5- (2,2-dimethoxycarbonylethyl) phenyl, 2,3-methylenedioxy-5- (2,2-dimethoxycarbonylvinyl) phenyl, 4- (2,2-dimethoxycar Carbonylethyl) -2-hydroxyphenyl, 2- (2,2-dimethoxycarbonylethyl) -4-hydroxyphenyl, 4- (2,2-dimethoxycarbonylvinyl) -2-hydroxyphenyl, 2- (2,2-dimethoxycarbonylvinyl) -4-hydroxyphenyl, 4- (2,2-dimethoxycarbonylethyl) -2- (2,2-dimethoxycarbonylvinyl) phenyl, 2 -(2,2-dimethoxycarbonylethyl) -4- (2,2-dimethoxycarbonylvinyl) phenyl group and the like.

As one group which is very suitable among the naphthyridine derivatives of this invention, the group containing each compound represented by following (1)-(6) is mentioned. Hereinafter, this group can be referred to as compound group A of the present invention.

(1) The naphthyridine derivative in which one of R ³ and R ⁴ in the formula (1) is a lower alkyl group.

(2) The naphthyridine derivative according to (1), wherein R ¹ is a hydrogen atom.

(3) The naphthyridine derivative according to the above (2), wherein R ² is a phenyl lower alkyl group which may have 1-3 lower alkoxy groups on the phenyl ring.

(4) The naphthyridine derivative according to (3), wherein Z is a single bond.

(5) The naphthyridine derivative according to the above (4), wherein R ⁵ is a phenyl group having 1-3 lower alkoxy groups as a substituent.

(6) The naphthyridine derivative according to the above (5), wherein R ² is a benzyl group which may have 1-3 lower alkoxy groups on the phenyl ring.

In the said compound group A of this invention, the compound shown to (4)-(6) has the characteristic which was especially excellent in pharmacological activity.

The other suitable 1 group among the naphthyridine derivatives of this invention can be mentioned the group containing each compound defined by following (7)-(9). Hereinafter, this group may be called compound group B of this invention.

(7) In the formula (1), one of R ³ and R ⁴ is a lower alkyl group, and Z is a naphthyridine derivative having a single bond.

(8) The naphthyridine derivative according to the above (7), wherein R ⁵ is a phenyl group having three lower alkoxy groups as a substituent.

(9) The naphthyridine derivative according to the above (7), wherein R ⁵ is a 3,4,5-tri lower alkoxyphenyl group.

In addition to having excellent pharmacological activity, each compound belonging to the compound group of the present invention has a feature of having extremely few side effects. Especially, the compound defined in (8) and (9) has the characteristic that its pharmacological activity is stronger.

The specific compound which belongs to the naphthyridine derivative of this invention suitable in terms of pharmacological activity and side effects is as showing to following (10).

(10) 1- (3,4,5-trimethoxybenzyl) -3- [methyl-2- (3,4,5-trimethoxyphenoxy) ethylsulfonium] -1,8-naphthyridine- 2 (1H) -one-4-oleate, 1-benzyl-3- [ethyl-3- (3,4,5-trimethoxyphenoxy) propylsulfonium] -1,8-naphthyridine-2 ( 1H) -one-4-oleate, 1-methyl-3- [methyl-2- (3,4,5-trimethoxyphenoxy) ethylsulfonium] -1,8-naphthyridine-2 (1H) -One-4-oleate, 1-benzyl-3- [methyl-3- (3,4,5-trimethoxyphenoxy) propylsulfonium] -1,8-naphthyridin-2 (1H) -one -4-oleate and 1- (4-methoxybenzyl) -3- [methyl-3- (3,4,5-trimethoxyphenoxy) propylsulfonium] -1,8-naphthyridine-2 ( 1H) -one-4-oleate.

Among them, 1-benzyl-3- [methyl-3- (3,4,5-trimethoxyphenoxy) propylsulfonium] -1,8-naphthyridin-2 (1H) -one-4-oleate Most preferred.

The naphthyridine derivative of the present invention can be produced by various methods. The example is given below by giving a reaction scheme.

In formula, R <^1> , R <^2> , R <^3> and R <^4> are as above. Ph means a phenyl group.

In Reaction Formula 1, compound (3) is first obtained by reacting compound (2) with iodinebenzene diacetate in the presence of an alkali. In the said reaction, water can be used suitably as a solvent, As an alkali, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, etc. can be used. It is preferable that the usage-amount of alkali and iodine benzene diacetate shall be 1 mol-excess amount with respect to 1 mol of raw material compounds, respectively. The reaction is carried out for about 1-10 hours in the temperature range near 0 ° C to room temperature.

Then, compound (1) of the present invention is obtained by reacting the obtained compound (3) with a thioether derivative (4). The said reaction can be performed using lower alcohols, such as methanol, ethanol, and trifluoroethanol, as a solvent, and adding appropriate amount of acid catalysts, such as p-toluenesulfonic acid and acetic acid. It is preferable that the usage-amount of a thioether derivative (4) shall be about 1-10 mol with respect to 1 mol of compounds (3). In addition, the usage-amount of an acidic catalyst can be 0.005-0.5 mol with respect to 1 mol of compounds (3). The reaction is completed in about 10 minutes to 24 hours in the range of room temperature to reflux temperature.

In the above, the compound (2) used as the starting raw material compound can be produced, for example, by the following method.

In the formula, R ¹ and R ² are the same as above. R represents a lower alkyl group.

The acetylation reaction of compound (5) shown in Scheme 2 is carried out by treating compound (5) in an excess amount of acetic anhydride at 100 ° C-reflux temperature for 10-100 hours. The cyclization reaction of the acetamide derivative (6) obtained by the above reaction is based on the presence of a base such as potassium-t-butoxide or sodium ethoxide in an aromatic hydrocarbon-based inert solvent such as toluene, xylene, mesitylene, cumene and cymene. Under heating the acetamide derivative (6). The preferred amount of base is about 1-5 times the molar amount relative to the starting compound. The heating temperature may be in the range of about 100 DEG C-reflux temperature, and the heating time may be in the range of about 0.5-5 hours.

It is thought that the compound (1) of the present invention obtained by the above reaction has a resonance structure shown below. Therefore, the compound of the present invention can be represented by any of the following structural formulas.

The compound of the present invention can be easily isolated and purified by ordinary separation and purification means. As said means, the various means generally usable, for example, adsorption chromatography, thin layer chromatography for refining, recrystallization, solvent extraction, etc. are mentioned.

In addition, in some of the compounds of the present invention, optical isomers having asymmetric centers of sulfur and / or carbon atoms exist. The present invention includes both racemates which are mixtures of such optical isomers and optically active agents which are each optical isomer. The said optical isomer can be isolate | separated according to the conventional dividing method, for example, the method of using a well-known optical dividing agent.

The compound of the present invention represented by the general formula (1) has an excellent analgesic action and is useful as a medicine, particularly an analgesic agent. Among them, it is effective for alleviating postoperative pain and cancerous pain. In addition, the compound of the present invention is also useful as an agent for treating diabetic neuropathy and an adenosine enhancer. In particular, the compound of the present invention has a feature that the side effects such as thyroid hypertrophy are hardly observed as compared to the naphthyridine derivative developed by the present inventor.

Therefore, this invention provides the pharmaceutical composition containing the compound of this invention represented by the said General formula (1) as an active ingredient. The said pharmaceutical composition is adjusted to practical use of the form of a general pharmaceutical agent using the compound of this invention, and a pharmaceutically acceptable carrier.

As a pharmaceutically acceptable carrier used in the pharmaceutical composition of the present invention, diluents or excipients commonly used according to the use form of the preparation, for example fillers, extenders, binders, dehumidifying agents, disintegrating agents, surfactants, lubricants and the like It can be illustrated. These are suitably selected and used according to the dosage unit form of the pharmaceutical agent adjusted.

The dosage unit form of a pharmaceutical agent can select various forms suitably according to a therapeutic purpose. Typical examples thereof include tablets, pills, powders, solutions, suspensions, emulsions, granules, capsules, suppositories, injections (liquids, suspensions, etc.), ointments, and the like.

In molding in the form of tablets, pharmaceutically acceptable carriers include, for example, excipients such as lactose, white sugar, sodium chloride, glucose, urea, starch, calcium carbonate, kaolin, crystalline cellulose, silicic acid and potassium phosphate; Binders such as water, ethanol, propanol, short syrup, glucose solution, starch solution, gelatin solution, carboxymethyl cellulose, hydroxypropyl cellulose, methyl cellulose and polyvinyl pyrrolidone; Disintegrating agents such as sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, low-substituted hydroxypropyl cellulose, dried starch, sodium alginate, agar powder, naminaran powder, sodium hydrogencarbonate, calcium carbonate; Surfactants such as polyoxyethylene sorbitan fatty acid esters, sodium lauryl sulfate, stearic acid monoglycerides; Disintegration inhibitor groups such as sucrose, stearin, cacao butter and hydrogenated oil; Absorption accelerators such as quaternary ammonium base and sodium lauryl sulfate; Moisturizing agents such as glycerin and starch; Adsorbents such as starch, lactose, kaolin, bennitite and colloidal silicic acid; Lubricants such as purified talc, stearate, boric acid powder and polyethylene glycol can be used. In addition, tablets can be prepared as usual tablets, such as dragee tablets, gelatin coated tablets, enteric tablets, film-coated tablets or double-coated tablets, and multi-layered tablets, if necessary.

In molding in the form of pills, as a pharmaceutically acceptable carrier, for example, excipients such as glucose, lactose, starch, cacao oil, hardened vegetable oil, kaolin, talc; Binders such as gum arabic, tragant, gelatin and ethanol; With lamina, disintegrating agents such as agar can be used.

In molding in the form of suppositories, as the pharmaceutically acceptable carrier, for example, polyethylene glycol, cacao oil, higher alcohols, esters of higher alcohols, gelatin, semisynthetic glycerides and the like can be used.

Capsules are generally prepared by mixing the compounds of the present invention with the various pharmaceutically acceptable carriers exemplified above, and filling the mixture with hard gelatin capsules, soft gelatin capsules and the like according to the conventional method.

When the compounds of the present invention are prepared as injections such as liquids, emulsions, suspensions and the like, these are preferably sterilized and isotonic with blood. In these forms, as a diluent, for example, water, ethanol, macrogol, propylene glycol, ethoxylated isostearyl alcohol, polyoxylated isostearyl alcohol, polyoxyethylene sorbitan fatty acid ester and the like can be used. . In this case, a sufficient amount of salt, glucose or glycerin to prepare an isotonic solution can be contained in the pharmaceutical preparation, and a conventional dissolution aid, buffer, analgesic agent, or the like can be added.

In preparing in the form of ointments such as pastes, creams, gels, and the like, for example, white petrolatum, paraffin, glycerin, cellulose derivatives, polyethylene glycol, silicone, bentonite, and the like can be used.

Moreover, the pharmaceutical composition of this invention can also be made to contain a coloring agent, a preservative, a fragrance | flavor, a flavoring agent, a sweetener, etc., and other pharmaceutical products as needed.

The amount of the compound (active ingredient compound) of the present invention to be blended in the pharmaceutical composition of the present invention is not particularly limited and is appropriately selected from a wide range. Usually in the pharmaceutical composition, it is preferably formulated at about 0.5-90% by weight, preferably about 1-85% by weight.

The method of administration of the pharmaceutical preparation of the present invention is not particularly limited and may be determined according to various types of preparations, age, sex and other conditions of the patient, degree of disease, and the like. For example, tablets, pills, solutions, suspensions, emulsions, granules, and capsules are administered orally, and injections can be administered alone or in admixture with conventional solutions such as glucose, amino acids, intravenously, intramuscularly, intracutaneously, subcutaneously. Or intraperitoneally, and suppositories are administered rectally.

The dosage of the pharmaceutical preparation of this invention is suitably selected according to the usage, the age, sex, and other conditions of a patient, the grade of a disease, etc. In general, the amount of the compound of the present invention, which is an active ingredient, is about 0.5-20 mg per kg of body weight per adult, preferably about 1-10 mg. The formulations may be administered once per day or divided into 2-4 times.

Hereinafter, in order to demonstrate this invention further in detail, the manufacture example of a raw material compound is mentioned as a reference example for manufacture of the compound of this invention, and the example of preparation of a compound of this invention is then given as an example.

In each example, ¹ H-NMR was measured using tetramethylsilane (TMS) as an internal standard in dimethyl sulfoxide-D ₆ (DMSO-d ₆ ) solvent, unless otherwise specified.

Reference Example 1

(1) Preparation of 1-benzyl-4-hydroxy-1,8-naphthyridin-2 (1H) -one

36.7 g of methyl 2-benzylaminonicotinate was dissolved in 400 ml of acetic anhydride and stirred at 160 ° C. for 48 hours. After completion of the reaction, acetic anhydride was distilled off under reduced pressure, and the residue was dissolved in 400 ml of diethyl ether, and washed twice with saturated aqueous sodium bicarbonate and then with water once. Then, the mixture was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain 39.0 g of methyl 2- (N-acetyl-N-benzyl) aminonicotinate as an oil phase.

Next, 22.5 g of the compound obtained above was dissolved in 300 ml of xylene, 21.3 g of potassium -t-butoxide was added at room temperature, and the mixture was stirred at 150 ° C for 2 hours. After cooling, the mixture was extracted with 250 ml of water, and an aqueous citric acid solution was added to the aqueous layer to adjust the pH of the aqueous layer to 3. The precipitated crystals were collected by filtration and washed with methanol to obtain 20.5 g of 1-benzyl-4-hydroxy-1,8-naphthyridin-2 (1H) -one crystal.

Melting Point: 250-253 ℃

¹ H-NMR (δ: ppm): 5.55 (2H, s), 5.97 (1H, s), 7.15-7.35 (6H, m), 8.26 (1H, d, J = 7.7), 8.60 (1H, d, J = 4.7), 11.79 (1H, broad singlet)

(2)-(8) Preparation of Each Compound

Each compound of following (2)-(8) was synthesize | combined similarly to said (1) using the suitable starting raw material.

(2) 4-hydroxy-1,8-naphthyridin-2 (1H) -one

Melting Point: 300 ℃ or higher

¹ H-NMR (δ: ppm): 5.76 (1H, s), 7.21 (1H, dd, J = 4.7, 7.7), 8.14 (1H, d, J = 7.7), 8.51 (1H, d, J = 4.7 ), 11.58 (2H, brs)

(3) 1- (4-methoxybenzyl) -4-hydroxy-1,8-naphthyridin-2 (1H) -one

Melting Point: 256-259 ℃

¹ H-NMR (δ: ppm): 3.69 (3H, s), 5.48 (2H, s), 5.96 (1H, s), 6.81 (2H, d, J = 8.7), 7.23 (2H, d, J = 8.7), 7.28 (1H, dd, J = 4.7, 7.7), 8.25 (1H, d, J = 7.7), 8.62 (1H, d, J = 4.7), 11.76 (1H, brs)

(4) 1- (3,4,5-trimethoxybenzyl) -4-hydroxy-1,8-naphthyridin-2 (1H) -one

Melting Point: 254-257 ℃

¹ H-NHR (δ: ppm): 3.60 (3H, s), 3.67 (6H, s), 5.47 (2H, s), 5.96 (1H, s), 6.60 (2H, s), 7.30 (1H, dd) , J = 4.7, 7.7), 8.26 (1H, d, J = 7.7), 8.64 (1H, d, J = 4.7), 11.80 (1H, brs)

(5) 1-benzyl-4-hydroxy-7-methyl-1,8-naphthyridin-2 (1H) -one

Melting Point: 261-264 ℃

¹ H-NMR (δ: ppm): 2.49 (3H, s), 5.49 (2H, s), 5.87 (1H, s), 7.10 (1H, d, J = 7.9), 7.12-7.29 (5H, m) , 8.09 (1H, d, J = 7.9), 11.78 (1H, brs)

(6) 4-hydroxy-1-n-propyl-1,8-naphthyridin-2 (1H) -one

Melting Point: 257-259 ℃

¹ H-NMR (δ: ppm): 0.89 (3H, t, J = 7.4), 1.51-1.68 (2H, m), 4.26 (2H, t, J = 7.4), 5.89 (1H, s), 7.28 ( 1H, dd, J = 4.5, 7.6), 8.23 (1H, d, J = 7.6), 8.64 (1H, d, J = 4.5), 11.70 (1H, brs)

(7) 1-cyclohexyl-4-hydroxy-1,8-naphthyridin-2 (1H) -one

Melting Point: 265-268 ℃

¹ H-NMR (δ: ppm): 1.11-1.91 (8H, m), 2.58-2.88 (2H, m), 5.30-5.67 (1H, m), 5.85 (1H, s), 7.26 (1H, dd, J = 4.7, 7.7), 8.21 (1H, d, J = 7.7), 8.63 (1H, d, J = 4.7) 11.57 (1H, brs)

(8) 4-hydroxy-1-phenyl-1,8-naphthyridin-2 (1H) -one

Melting Point: 288-290 ℃

¹ H-NMR (δ: ppm): 5.94 (1H, s), 7.17-7.30 (3H, m), 7.35-7.52 (3H, m), 8.26 (1H, d, J = 7.9), 8.39 (1H, d, J = 4.7), 11.51 (1H, broad s)

(9) Preparation of 1-benzyl-3-phenyliodonium-1,8-naphthyridin-2 (1H) -one-4-oleate

3.1 g (29 mmol) of sodium carbonate was dissolved in 200 ml of water, and 7.0 g (28 mmol) of the compound of the above (1) was dissolved in this aqueous solution, followed by 9.0 g (28 mmol) of iodinebenzene diacetate at room temperature. Was added and stirred for 5 hours. After the completion of the reaction, the precipitated crystals were collected by filtration, washed sequentially with water, methanol and ether, and dried under reduced pressure at room temperature for 20 hours to obtain 10.1 g of the title compound.

Melting Point: 147-149 ° C (Decomposition)

¹ H-NMR (δ: ppm): 5.56 (2H, s), 7.11-7.26 (6H, m), 7.33-7.54 (3H, m), 7.84 (2H, d, J = 7.4), 8.32 (1H, d, J = 7.4), 8.50 (1H, d, J = 4.5)

(10)-(16) Preparation of the following Compounds

Each compound of following (10)-(16) was synthesize | combined similarly to said (9) using the suitable starting raw material.

(10) 3-phenyliodonium-1,8-naphthyridin-2 (1H) -one-4-oleate

Melting Point: 300 ℃ or higher

¹ H-NMR (δ: ppm): 7.10 (1H, dd, J = 4.7, 7.7), 7.35-7.53 (3H, m), 7.81 (2H, d, J = 7.4), 8.20 (1H, d, J = 7.7), 8.42 (1H, d, J = 4.7), 11.01 (1H, s)

(11) 1- (4-methoxybenzyl) -3-phenyliodonium-1,8-naphthyridin-2 (1H) -one-4-oleate

Melting Point: 128-130 ℃

¹ H-NMR (δ: ppm): 3.68 (3H, s), 5.48 (2H, s), 6.80 (2H, d, J = 8.9), 7.15 (1H, dd, J = 4.9, 7.9), 7.22 ( 1H, d, J = 8.9), 7.36-7.55 (3H, m), 7.84 (1H, d, J = 7.4), 8.31 (1H, d, J = 7.9), 8.51 (1H, d, J = 4.9)

(12) 3-phenyliodonium-1- (3,4,5-trimethoxybenzyl) -1,8-naphthyridin-2 (1H) -one-4-oleate

Melting Point: 132-134 ℃

¹ H-NMR (δ: ppm): 3.58 (3H, s), 3.60 (3H, s), 5.48 (2H, s), 6.56 (2H, s), 7.16 (1H, dd, J = 4.7, 7.7) , 7.35-7.55 (3H, m), 7.86 (2H, d, J = 7.7), 8.33 (1H, d, J = 7.7), 8.52 (1H, d, J = 4.7)

(13) 1-benzyl-7-methyl-3-phenyliodonium-1,8-naphthyridin-2 (1H) -one-4-oleate

Melting Point: 139-140 ℃

¹ H-NMR (δ: ppm): 2.47 (3H, s), 5.53 (2H, s), 7.01 (1H, d, J = 7.9), 7.10-7.53 (8H, m), 7.83 (2H, d, J = 8.4), 8.20 (1H, d, J = 7.9)

(14) 3-phenyliodonium-1-n-propyl-1,8-naphthyridin-2 (1H) -one-4-oleate

Melting Point: 133-135 ℃

¹ H-NMR (δ: ppm) [CDCl ₃ ]: 0.91 (3H, t, J = 7.5), 1.45-1.61 (2H, m), 4.20 (2H, t, J = 7.6), 7.04 (1H, dd , J = 4.6, 7.6), 7.32-7.50 (3H, m), 7.94 (2H, d, J = 8.5), 8.38 (1H, d, J = 7.6), 8.47 (1H, d, J = 4.6)

(15) 1-cyclohexyl-3-phenyliodonium-1,8-naphthyridin-2 (1H) -one-4-oleate

Melting Point: 136-138 ℃

¹ H-NMR (δ: ppm): 1.13-1.87 (8H, m), 2.50-2.75 (2H, m), 5.30-5.50 (1H, m), 7.14 (1H, dd, J = 4.6, 7.7), 7.35-7.53 (3H, m), 7.83 (2H, d, J = 8.2), 8.30 (1H, d, J = 7.7), 8.53 (1H, d, J = 4.6)

(16) 1-phenyl-3-phenyliodonium-1,8-naphthyridin-2 (1H) -one-4-oleate

Melting Point: 141-143 ° C

¹ H-NMR (δ: ppm) [CDCl ₃ ]: 7.07 (1H, dd, J = 4.6, 7.6), 7.22 (1H, d, J = 7.3), 7.31-7.56 (6H, m), 8.01 (2H , d, J = 7.6), 8.39 (1H, d, J = 4.6), 8.49 (1H, d, J = 7.6) (17)-(20) Preparation of the following compounds

Each compound of following (17) and (18) was synthesize | combined similarly to said (1) using the suitable starting raw material. Moreover, each compound of following (19) and (20) was synthesize | combined similarly to said (9) using the suitable starting raw material.

(17) 1-ethyl-4-hydroxy-1,8-naphthyridin-2 (1H) -one

(18) 4-hydroxy-1-methyl-1,8-naphthyridin-2 (1H) -one

(19) 1-ethyl-3-phenyliodonium-1,8-naphthyridin-2 (1H) -one-4-oleate

(20) 1-methyl-3-phenyliodonium-1,8-naphthyridin-2 (1H) -one-4-oleate

Example 1

Preparation of 1-benzyl-3- [methyl-3- (3,4,5-trimethoxyphenoxy) propylsulfonium] -1,8-naphthyridin-2 (1H) -one-4-oleate

To 20 ml of trifluoroethanol, 2.3 g (5.1 mmol) of the compound of the above (9), 1.7 g (6.2 mmol) of methyl-3- (3,4,5-trimethoxyphenoxypropyl) sulfide and 30 mg of p-toluenesulfonic acid was dissolved and stirred at room temperature for 30 minutes. After the completion of the reaction, trifluoroethanol was distilled off and the residue was purified by silica gel column chromatography (developing solvent: methanol / chloroform = 1/25), and the obtained crystal was washed with methanol to obtain 2.4 g of the target compound. .

Example 2-38

In the same manner as in Example 1, the compound of the present invention having a structure shown in the following Table was synthesized. The melting point and ¹ H-NMR analysis result of each compound obtained in each following table are shown.

Pharmacology exam 1

Therapeutic Effect of Diabetic Neurosis

Models were prepared by intravenously administering 50 mg / kg of streptozotocin (STZ) dissolved in 0.01 M citric acid buffer to 8-week-old male SD rats. After administration, 5 rats were raised in cages.

After 3 weeks of STZ administration, the Randall-Selitto method [Randall, LO and Selitto, JJ Arch. lnt. Pharmacodyn., 111 , 409-419 (1957)], measured the threshold of pain in the left foot of each rat for pre-stimulation. Animals whose total value was 30 mmHg or less were selected, and 3 groups of 1 to 8-10 animals were prepared (n = 8-10).

In the test animals of group 1 (experimental group) divided into the above groups, 5% Arabian rubber solution containing the test compound was used as a sample, so that the amount of one dose compound was 30 mg / kg and the amount was 10 ml / kg. Once daily, oral administration was continued for 21 days. In addition, another group was used as a control group, and the test animals of the control group were orally administered once daily for 10 days / 21 days with a dose of 10 ml / kg as a sample with only 5% gum arabic. In addition, a group was administered in which no sample was administered (untreated group).

Three hours after the administration on the 14th and 21st day of administration, the pain threshold of the left foot of each test animal was measured, and the recovery rate was obtained according to the following formula.

(Wherein T represents the mean of the experimental group, C the mean of the control group, and N represents the mean of the untreated group)

The results obtained are shown in Table 13 below.

Test compound % Recovery Day 14 Day 21 Example 1 46.2 56.7

From the results shown in Table 13, it can be seen that the compound of the present invention exhibits an excellent therapeutic effect of diabetic neuropathy.

Pharmacology exam 2

Adenosine Enhancer

As the test compound, each compound obtained in Examples 1 and 34 was used in the form of a dimethyl sulfoxide solution.

As a test animal, Hartley-type male morphot (purchased from Nippon Rivers River) was used (more than 6 days after the arrival, and the good thing of the general state was used).

Animals were kept in a breeding room set at a temperature of 20-26 ° C (measured value: 22.1-22.9 ° C), humidity 40-70% (measured value: 50.3-51.5%), and lighting time 12 hours / day (7: 00-19: 00). Breeding. Feed was fed freely with solid feeds (Labo G-Standard, Nihon-no-san), and water was fed freely with tap water.

The following experiment was performed using the extraction site (n = 2) of test animals (weight at use: 316-388 g). In other words, after desalting slaughter of the feed animal, the ileum was extracted, and a bath filled with a nutrient solution (Krebs-Henseleit liquid; liquid amount = 10 mL, liquid temperature = 32 ° C.) passed through a mixed gas of 95% oxygen + 5% carbon dioxide. bath) at a load of 0.5 g. Shrinkage due to light wall electric stimulation is performed by using an electric stimulation device (Nihon Koden Industries, SEN-3301) and a channel bath driver amplifier (Nihon Koden Industries, SEG-3104), through a ring-shaped platinum electrode, Frequency: 0.1 Hz, duration: 5 msec, voltage: less than maximum voltage (V)). The shrinkage reaction of the specimen was recorded on an ink writing recorder (Graphtech, SR-6211, SR-6221) through an isotonic transducer (Nihon Koden Industries, TD-112S).

The samples were left in the nutrient solution for 30 to 60 minutes while the nutrient solution was exchanged about every 20 minutes, and then electrostimulated. After the shrinkage reaction was stabilized, 10 ^-6 M to 10 ^-5 M of adenosine (Wako Pure Chemical Industries, Ltd.) were added to investigate the shrinkage suppression reaction. That is, the nutrient solution was exchanged, 15 minutes after the electrical stimulation, adenosine 10 ⁻⁶ M to 10 ⁻⁵ M was added cumulatively in a stable place, and the dose-response curve of adenosine was calculated to calculate an ED ₅₀ value.

The test compound is given where again stable electrical stimulation shrinkage exchange youngyangaek, and after 15 minutes, final concentration 10 ^-7 M, 10 ^-6 M and 10 ^-5 M, and after the addition to, acting for 5 minutes, adenosine ^10-6 A dose-response curve of adenosine was obtained by cumulative addition of M to ^10-5 M, and the ED ₅₀ value [ED ₅₀ (+)] of adenosine in the presence of the test compound was calculated.

As a ratio (ED ₅₀ (−) / ED ₅₀ (+)) to the ED ₅₀ value [ED ₅₀ (−)] in the absence of the test compound, the adenosine enhancement effect of the test compound was determined.

The obtained results are shown in Table 14 below.

Test compound Concentration (m) Adenosine Enhancer (ED ₅₀ (-) / ED ₅₀ (+)) Example 1 10 ^-6 11.11 Example 34 10 ^-5 14.00

The results shown in Table 14 show that the compound of the present invention has a strong adenosine enhancement effect.

Pharmacology Exam 3

Analgesic effect test

Two groups of experimental and control groups consisting of seven male 6-week-old male rats were prepared, and first, the pain threshold of the left hind paw of each group rat was measured using a pressure-stimulating analgesic effect measuring apparatus (manufactured by Unicom). Earthwork [Randall, L.0. and Sellitto, JJ, Arch. lnt. Pharmacodyn., 111 , 409-419 (1957)]. The obtained value is called "full value."

After 1 hour of measurement of the total value, the experimental group contained 5% arabic rubber suspension containing a compound of the present invention and the control group contained 5% arabic rubber suspension (not including the compound of the present invention) at a rate of 10 ml / kg, respectively. Oral administration.

One hour after the oral administration, a physiological saline solution of Substance P (25 ng / 0.1 mL) was injected subcutaneously in the left hind paw of each rat.

Next, after a predetermined time elapsed from the substance P scan, the pain threshold of the left hind paw of each group rat was measured as described above, and this was referred to as a "post-value".

From the measured values (after and before) of each group, the pain threshold recovery rate (%) was calculated according to the following equation.

The obtained results (maximum recovery rate) are shown in Table 15 below.

Test compound % Recovery In measurement (after minutes) Example 1 46 60 Example 15 39 60 Example 36 111 60

From the results shown in Table 15, it is clear that the compounds of the present invention obtained in Examples 1, 15 and 36 each exhibited excellent analgesic action.

In addition, each compound shown in following Table 16 and Table 17 can be manufactured like each said Example. Each of these compounds belongs to (8) of the compound group B of the present invention described above. Each of these compounds is considered to show substantially the same results as the results shown in Tables 13-15 by the tests shown in the respective pharmacological test examples.

Formulation Example 1

As an active ingredient, using the compound of the present invention obtained in Example 1, a tablet (2000 tablets) containing 300 mg per tablet was prepared according to the following prescription.

600 g of the compound of the present invention obtained in Example 1

Lactose (Japan Drug Store) 67 g

33 g of corn starch (Japan Drug Store article)

25 g of carboxymethyl cellulose calcium (Japan Drug Store article)

12 g of methyl cellulose (Japan Drug Store article)

3 g of magnesium stearate (Japan Drug Store article)

That is, according to the prescription, the compound of the present invention, lactose, corn starch and carboxymethyl cellulose calcium obtained in Example 1 are sufficiently mixed, the mixture is granulated using an aqueous solution of methyl cellulose, and passed through a 24 mesh sieve, This was mixed with magnesium stearate and pressed into tablets to obtain the desired tablets.

Formulation Example 2

Using the compound of the present invention obtained in Example 25 as an active ingredient, a hard gelatin capsule (2000 capsules) containing 200 mg of this per capsule was prepared according to the following prescription.

400 g of the compound of the present invention obtained in Example 25

60 g of crystalline cellulose (Japan Drug Store article)

34 g of corn starch (Japan Drug Store article)

4 g of talc (Japanese Pharmacy Defense Products)

2 g of magnesium stearate (Japan Drug Store article)

That is, according to the above formulation, each component was finely powdered and mixed to form a uniform mixture, and then filled into oral administration gelatin capsules having desired dimensions to obtain desired capsules.

Claims (22)

Naphthyridine derivative represented by the following formula (1). <Formula 1> Wherein R ¹ represents a hydrogen atom or a lower alkyl group; R ² represents a hydrogen atom, a lower alkyl group, a cycloalkyl group, a phenyl group or a phenyl lower alkyl group which may have 1-3 lower alkoxy groups on the phenyl ring; R ³ and R ⁴ are each a group -YOZR ⁵ (wherein Y is a lower alkylene group, Z is a single bond or a lower alkylene group, and R ⁵ is a halogen atom as a substituent, a lower alkoxy group, a lower alkyl group, a halogen substituted lower alkyl group). , Phenyl group having 1-3 groups selected from the group containing methylenedioxy group, hydroxy group, 2,2-di (lower alkoxycarbonyl) ethyl group and 2,2-di (lower alkoxycarbonyl) vinyl group) Or one of R ³ and R ⁴ is a group -YOZR ⁵ (wherein Y, Z and R ⁵ are the same as above) and the other represents a lower alkyl group, a phenyl group or a phenyl lower alkyl group, provided that R ² is phenyl A phenyl lower alkyl group which may have 1 to ³ lower alkoxy groups on the ring, except that at least one of R ³ and R ⁴ is a benzyloxy lower alkyl group having 1 to 3 lower alkoxy groups on the benzene ring. The naphthyridine derivative according to claim 1, wherein one of R ³ and R ⁴ is a lower alkyl group. The naphthyridine derivative according to claim 1, wherein R ¹ is a hydrogen atom and ^one of R ³ and R ⁴ is a lower alkyl group. The method of claim 1, wherein R ¹ is a hydrogen atom, R ² is a phenyl lower alkyl group which may have 1-3 lower alkoxy groups on the phenyl ring, and one of R ³ and R ⁴ is a lower alkyl group, characterized in that Naphthyridine derivatives. 2. A compound according to claim 1, wherein R ¹ is a hydrogen atom, R ² is a phenyl lower alkyl group which may have 1-3 lower alkoxy groups on the phenyl ring, and one of R ³ and R ⁴ is a lower alkyl group and Z is Naphthyridine derivatives, characterized in that a single bond. 2. A compound according to claim 1, wherein R ¹ is a hydrogen atom, R ² is a phenyl lower alkyl group which may have 1-3 lower alkoxy groups on the phenyl ring, and one of R ³ and R ⁴ is a lower alkyl group, and R ⁵ A naphthyridine derivative wherein Z is a phenyl group having 1 to 3 lower alkoxy groups as the substituent and Z is a single bond. 2. A compound according to claim 1, wherein R ¹ is a hydrogen atom, R ² is a benzyl group which may have 1 to 3 lower alkoxy groups on the phenyl ring, one of R ³ and R ⁴ is a lower alkyl group, and R ⁵ is A naphthyridine derivative wherein Z is a single bond and a phenyl group having 1-3 lower alkoxy groups as a substituent. The naphthyridine derivative according to claim 1, wherein one of R ³ and R ⁴ is a lower alkyl group and Z is a single bond. The naphthyridine derivative according to claim 1, wherein one of R ³ and R ⁴ is a lower alkyl group, R ⁵ is a phenyl group having three lower alkoxy groups as a substituent, and Z is a single bond. The naphthyridine derivative according to claim 1, wherein one of R ³ and R ⁴ is a lower alkyl group, R ⁵ is a 3,4,5-tri lower alkoxyphenyl group, and Z is a single bond. The compound of claim 1, wherein 1- (3,4,5-trimethoxybenzyl) -3- [methyl-2- (3,4,5-trimethoxyphenoxy) ethylsulfonium] -1,8- Naphthyridin-2 (1H) -one-4-oleate, 1-benzyl-3- [ethyl-3- (3,4,5-trimethoxyphenoxy) propylsulfonium] -1,8-naphthyridine -2 (1H) -one-4-oleate, 1-methyl-3- [methyl-2- (3,4,5-trimethoxyphenoxy) ethylsulfonium] -1,8-naphthyridine-2 (1H) -one-4-oleate, 1-benzyl-3- [methyl-3- (3,4,5-trimethoxyphenoxy) propylsulfonium] -1,8-naphthyridine-2 (1H ) -One-4-oleate and 1- (4-methoxybenzyl) -3- [methyl-3- (3,4,5-trimethoxyphenoxy) propylsulfonium] -1,8-naphthyridine Naphthyridine derivatives, characterized in that it is selected from -2 (1H) -one-4-oleate. The compound of claim 1, wherein 1-benzyl-3- [methyl-3- (3,4,5-trimethoxyphenoxy) propylsulfonium] -1,8-naphthyridin-2 (1H) -one-4 -Naphthyridine derivatives characterized in that they are oleates. A pharmaceutical composition comprising the naphthyridine derivative according to claim 1 and a pharmaceutically acceptable carrier. The pharmaceutical composition according to claim 13, which is an analgesic agent. The pharmaceutical composition according to claim 13, which is an agent for treating diabetic neuropathy. The pharmaceutical composition according to claim 13, which is an adenosine enhancer. An analgesic method comprising administering an effective amount of a naphthyridine derivative according to claim 1 to a patient in need of treatment. An effective amount of the naphthyridine derivative according to claim 1 is administered to a patient in need of treatment. A method for enhancing adenosine, wherein an effective amount of the naphthyridine derivative according to claim 1 is administered to a patient in need thereof. Use of a naphthyridine derivative according to claim 1 for the preparation of a pharmaceutical composition useful for analgesic treatment. Use of a naphthyridine derivative according to claim 1 for the preparation of a pharmaceutical composition useful for treating diabetic neurosis. Use of a naphthyridine derivative according to claim 1 for the preparation of a pharmaceutical composition useful for adenosine enhancement.